ruck

1. noun

a) The situation formed when a runner is brought to ground and one or more members of each side are engaged above the ball, trying to win possession of it; a loose scrum.

1873 Dandolo was constantly in the ditch, sometimes lying with his side against the bank, and had now been so hustled and driven that, had he been on the other side, he would have had no breath left to carry his rider, even in the ruck of the hunt. — Anthony Trollope, Phineas Redux, [ Chapter 16.]

b) Contesting a bounce or ball up; used appositionally in "ruck contest". Rucks also used collectively either of ruckmen or of ruckmen and ruck rovers, and occasionally used in place of "followers" (including rovers too).

1914At last, out of the ruck rose Verman, disfigured and maniacal. With a wild eye he looked about him for his trusty rake; but Penrod, in horror, had long since thrown the rake out into the yard. Naturally, it had not seemed necessary to remove the lawn-mower. The frantic eye of Verman fell upon the lawnmower, and instantly he leaped to its handle. Shrilling a wordless war-cry, he charged, propelling the whirling, deafening knives straight upon the prone legs of Rupe Collins. Booth Tarkington, Penrod, [ Chapter 23.]

2. verb

a) To crease or fold.

1917 "Will you come over now and try on your dress?" Ally asked, looking at her with wistful admiration. "I want to be sure the sleeves dont ruck up the same as they did yesterday." — Edith Wharton, Summer, [ Chapter 12.]

b) To become folded.